## Cobaya and CLASS: How do you set list parameters for CLASS through Cobaya

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
Tanvi Karwal
Posts: 10
Joined: April 10 2020
Affiliation: University of Pennsylvania

### Cobaya and CLASS: How do you set list parameters for CLASS through Cobaya

Hello!

CLASS run for a cosmology using a .ini file takes input for certain parameters through a comma-separated list. Eg.

Code: Select all

m_ncdm = 0.04, 0.04, 0.04

How does Cobaya pass such "list parameters" to CLASS? I'm not seeing anything in the theories/classy/classy.py code for Cobaya to interface with CLASS and set list parameters. I'm currently trying to modify theories/classy/classy.py myself to include such a feature, but if there's already a way to do this, please let me know!

Ultimately, I want to run a sampler individually varying each entry in the list. So, eg. m_ncdm[0], m_ncdm[1] and m_ncdm[2] are independently varied through coabaya for say an MCMC.

Thank you!
Tanvi